nct6775: Use clamp_val instead of SENSORS_LIMIT

SENSORS_LIMIT has been deprecated and was removed from the upstream kernel.

Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Improve temperature register array declarations

Specify explicit sizes for temperature register arrays.

Signed-off-by: Guenter Roeck <linux@roeck-us.net>